The present invention relates to bumpers having thermoplastic energy absorbers with crush lobes that crush to absorb a uniform and predictable amount of energy regardless of where impacted across a face of the bumper, and that are adapted with sensors to sense an impact. More particularly, the present invention relates to energy absorbers particularly designed for reduced injury upon impacting a pedestrian, and including an elongated impact sensor on the energy absorber.
Existing bumper systems include reinforcement beams and energy absorbers with crush lobes tuned to provide a desired impact resistance and energy absorption (i.e. a desired force-deflection curve). However, improvements are desired in the areas of improved pedestrian safety (e.g. reduced leg injury during an impact, regardless of impact location), and having the ability to reliably sense accidents and to optimally respond to varied impact severities (and for example, to pass barrier impact testing and also pedestrian leg injury minimization testing using a FLEX PLI test apparatus). Also, a design is desired having design flexibility, yet that provides consistency of crush lobe geometry and shape, and that is more easily moldable and tunable to a specific energy absorption force-deflection impact-receiving occurrence. Also, a design is desired having an integrated impact sensor carried in a position causing reliable and quick sensing of impacts.